Liste des communications
Synthesis and characterization of CuxSixFe2-2xOspinnelferrites produced by the ceramic technic4
Spinel copper ferrites Cu1+xMxFe2-2xO(M=Si) with(0.2 x 0.5) were synthesized by the double sintering ceramic4technique and characterized using X-ray diffraction VSM andSEM, diffraction patterns show that all samples have a singlephase.the magnetic properties of the nanocomposites wereinvestigated, the scanning electron microscope (SEM) with EDSanalyser were performed to show micrographs aggregates andconfirm the stoichiometry of the compound. Voir les détails
Mots clés : Cu-Ti Ferrites, Spinel, XRD, VSM, SEM, EDS
The experimental behavior of slabs strengthened byfiber reinforced polymer (CFRP)
The experimental behaviour of slabsstrengthened by composite fiber reinforced polymer (CFRP)is presented in this paper three concrete slabs of 16 cm x 14cm x 4 cm were made in laboratory conditions. Thedimensions of the patches are calculated so that the ratiopatch XP /YP is proportional to XD/ YD of the slab.Dimensions of the composite patches are: 70x90x1 mm,100x120x1mm, 160x140x1mm, the load is flexionalpunching load. The results given in the form of curves ofloads - displacements measured to the centric of the slabaccording to the force applied; show that the breaking loadand ultimate correspondent displacement are influenced bythe properties of the composite patch and the surface coveredby the composite patch. It is observed that, the breaking loadand ultimate displacement increase with the surface of thepatch and properties of the composite. The third slab havethe best behavior than the rest of slabs, the ratio of thedisplacement between the third and the second slab is 1.39and the ratio between the third and the first slab is 1,95. Voir les détails
Mots clés : Concrete slabs, composites, reinforcement, experiments.
PHYSICO-CHEMICAL ANALYSIS OF COMPOSITEMATERIALS (ALGINATE-BENTONITE-ACTIVATEDCARBON)
New low cost materials consisting of alginate,bentonite and activated carbon were prepared according to theionic gelation method. Physical characteristics of composites werecharacterised by X-ray diffraction, Fourier transform infraredspectroscopy, surface mesurment by Brunauer, Emmett and Tellermethod (BET), and morphological characterization by SEM. Alginatebeads containing activated carbon and bentonite have beensuccessfully applied for water treatment. Voir les détails
Mots clés : encapsulation, composite beads, characterization.
Thermal behavior of Functionally Graded Materials
Mathematical expressions have been used to findthermal behavior of functionally graded plate. Temperaturedistributions are used on the basis of three different types toevaluate the thermal properties of FGMs. Material properties arevary continuously through the thickness according to a powerlaw function, exponential function, and sigmoid function in termsof the volume fraction of the constituents. The computationalmathematical software Matlab.R2014b has been used to carry outthe numerical calculations and the graphs been plotted usingOriginLab.9. Voir les détails
Mots clés : Functionally graded materials, Material properties, Temperature distribution
The effect of Sintering condition on the microstructure and ElectricalConductivity of Apatite- type La9.33(SiO4)6O2ceramic
Rare-earth apatite-type lanthanum silicates, La9.33(SiO4)6O2.is prepared in air by the conventional solid statereaction for solid oxide electrolyte. The microstructure and electrical properties of La2 ,9.33(SiOceramic areinvestigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical impedancespectroscopy (EIS).The principal objective is the study of the effect of the sintering condition(time, temperature),on the morphology and the electrochemical properties of this phase. La9.33(SiO4)6O2 ceramic consist of ahexagonal apatite type structure and a small amount of a second phase of La2SiO52due to the law temperature ofsintering.Electrical properties of the sample have been studied between 302 and 802°C by the complex impedancemethod. The results of the conductivity measurements obtained between 302 and 605°C are treated first, in thetotal form of the sample, and then, by separating the grain from the grain boundary. Electrical conductivity of theLa9,33(SiO4)6O2apatite-type was found of a value of 1.04 10-3S.cm-1at 605°C. This value is higher than thatobtained with yttria stabilized zirconia(YSZ) at the same intermediate temperatures. Voir les détails
Mots clés : electrolyte, Apatite, Lanthanum silicate, Ionic conductivity
Vegard's Law in the Si1-yCyalloys
In this work, we presented a calculated ofstructural properties of the Si1-yCbinary alloys, the atomicstructure of this alloys is important for understanding itsproperties. We used theories of bond-length of Vegardsapproach based of the method of linear augmented plane wave(FP-LAPW) based on the theory of density functional (DFT). Wealso studied the structural properties of this alloys with the LDAapproximation for the potential for exchange and correlation.Our study affirms that the lattice constant is approximately equalto the composition-weighted average of the lattice constants ofthe pure materials. Voir les détails
Mots clés : Vegarslaw, Structural properties, SiC
Modélisation et Simulation Numérique desEngrenages Plastiques (PVC, PA)à DentureHélicoïdale sous un Environnement C.A.O"Application du Logiciel SolidWorks 2013+ Comsol4.4"
les recherches dans le domaine des engrenages sontpenchés vers lamélioration du rendement, et la diminution dubruit que provoque cette transmission et ce parlamélioration des caractéristiques des matériaux utilisés oupar létude dautre matériaux comme les matériaux plastiques.Dans cette étude nous avons présenté une simulation numériqueet aussi lanalyse statique et dynamique des engrenagesplastiques sous un environnement C.A.O, cette simulation sefait à laide des logiciels CosmosWorks intégré à SolidWorks+Comsol 4.4. Voir les détails
Mots clés : Engrenages Plastiques, Conception Innovante, Cosmos Works, PVC, PA
Mechanical Characterization of a new hybridJute/ Glass reinforced laminates
The greatest challenge, nowadays, in all science fields is toface the rarefaction of fossil resources. The solution in civilengineering and in transportation is to lighten theconstruction materials. For this end, the compositematerials have been, logically, i mposed since the secondhalf of the past century thanks to their specific mechanicalcharacteristics. In the two last decades, extraction and useprocedures of natural fibers have known an i mportantincrease for the reinforcement of composite materialscalledBiocomposites.This category of fibers possesses a lot of advantages uponthose traditional synthetic such as: Abundantly available,reduced cost, lightness and satisfactory specificperformances. The current study has the ai m ofcharacterizing a new hybrid laminate made up of 4 plies; theupper and lower ones are reinforced with glass mat fabricswhile the two central ones are reinforced with natural Jutewoven fabrics.The main idea of this work is to preserve sufficientmechanical characteristics by reinforcing the most solicited Voir les détails
Mots clés : composite materials, natural fibers, laminates, hybrid reinforcement.
Élaboration et Caractérisation des MembranesNano-bio-composites
Lévolution des matériaux polymères est passéeprincipalement sur le développement des matériaux nano-composites [1], laugmentation continue et lutilisation de cesmatériaux causent des dégâts irréversibles qui nuisent àlenvironnement de façon inquiétante. Pour cela, ces dernièresannées les industriels sintéressent aux nano-bio-composites pourremédier à certaines complications nuisibles. En dépit, deséléments naturels et biodégradables sont utilisés pour leurapplications variables dans différents secteurs (biomédical,alimentaire, agricole)[2].Nous nous intéressons dans ce travail, aux nano-bio-compositesChitosane/PVA/Na-MMT. Les résultats de la DRX ont montré laréussite du traitement de largile fig.1. Le test mécanique entraction et dabsorption deau, ont montré que largile traité NaMMTaméliore le module de Young des mélange polymèreCH/PVA, et le taux dabsorption, respectivement. LanalyseMEB/EDS a bien montrée la bonne dispersion des particulesdargile dans les phases polymériques. Voir les détails
Mots clés : nano-bio-composite, Na-MMT, Chitosane, PVA.
Thermo-mechanical beahvior of steel-concretecomposite columns under natural fireincluding heating and cooling phases
In recent years, concrete filled tubular(CFT) columns have become popular among designersand structural engineers, due to a series of highlyappreciated advantages: high load-bearing capacity,high seismic resistance, attractive appearance, reducedcolumn footing, fast construction technology and highfire resistance without external protection. In a fire, thedegradation of the material properties will cause CFTcolumns to become highly nonlinear and inelastic,which makes it quite difficult to predict their failure. Infact, it is possible to fail during heating or cooling phaseof fire. In this paper, the behavior of axially loadedconcrete filled square hollow section columns subjectedto natural fire conditions has been studied. The mainobjective of this study is to highlight the phenomenon ofdelayed collapse of this type of columns during or afterthe cooling phase of a fire, and then analyze theinfluence section size. The results show that criticalconditions with respect to delayed failure arise muchmore for massive sections. Voir les détails
Mots clés : Natural fire, Fire resistance, composite column, cooling phase, residual strength